Pot odds tell you the minimum chance of winning you need to make a call break even, and you get the answer by dividing the call by the pot after you call. If the pot is $100 and your opponent bets $50, you call $50 to win $150, so you need 25% equity. If your draw completes more often than that, calling is the right play on price.
The formula
Pot odds can be written two ways. Use whichever you find easier, since they say the same thing.
As a percentage (required equity):
Required equity = call ÷ (pot + bet + call)
Here “pot” is what was in the middle before the bet, “bet” is your opponent’s bet, and “call” is what you add. That makes the denominator the final size of the pot if you call.
As a ratio:
Pot odds = (pot + bet) : call
For a $50 bet into a $100 pot, that is $150 : $50, or 3 to 1. A ratio of 3 to 1 corresponds to 1 ÷ (3 + 1) = 25%. To convert, equity = 1 ÷ (ratio + 1).
Required equity at common bet sizes
Assume your opponent bets a fraction of the pot, and you face that bet. The table gives the equity you need to call.
| Bet size (fraction of pot) | Pot odds | Equity needed |
|---|---|---|
| 1/4 pot | 5 to 1 | 16.7% |
| 1/3 pot | 4 to 1 | 20.0% |
| 1/2 pot | 3 to 1 | 25.0% |
| 2/3 pot | 2.5 to 1 | 28.6% |
| 3/4 pot | 2.33 to 1 | 30.0% |
| Pot | 2 to 1 | 33.3% |
| 2x pot | 1.5 to 1 | 40.0% |
The formula behind it for a bet of B into a pot of P is B ÷ (P + 2B). Larger bets demand more equity, but never more than 50% however big the bet gets.
Outs and equity
An out is a card that improves your hand to the best one. To use pot odds, you need your chance of hitting an out. That is a counting problem.
After the flop you see five cards (your two plus three board cards), so 47 are unseen. After the turn, 46 are unseen.
- One card to come: chance = outs ÷ unseen cards.
- Two cards to come (flop to river): chance = 1 − (miss on turn × miss on river), which is 1 − [(47 − outs) ÷ 47] × [(46 − outs) ÷ 46].
For example, a flush draw has 9 outs (the 13 cards of your suit minus the 4 you can see). On the flop to the river:
1 − (38/47 × 37/46) = 1 − 0.650 = 0.350, or 35.0%.
The draw odds chart
| Outs | Typical draw | Next card only (turn) | Flop to river | Rule of 4 |
|---|---|---|---|---|
| 1 | One specific card needed | 2.1% | 4.3% | 4% |
| 2 | Pocket pair to a set | 4.3% | 8.4% | 8% |
| 3 | - | 6.4% | 12.5% | 12% |
| 4 | Gutshot straight draw | 8.5% | 16.5% | 16% |
| 5 | - | 10.6% | 20.4% | 20% |
| 6 | Two overcards | 12.8% | 24.1% | 24% |
| 7 | - | 14.9% | 27.8% | 28% |
| 8 | Open-ended straight draw | 17.0% | 31.5% | 32% |
| 9 | Flush draw | 19.1% | 35.0% | 36% |
| 10 | - | 21.3% | 38.4% | 40% |
| 12 | Flush draw plus a gutshot | 25.5% | 45.0% | 48% |
| 15 | Flush draw plus an open-ended draw | 31.9% | 54.1% | 60% |
The “one card” column is also the chance on the river alone from the turn, with a slightly different denominator (46 unseen): 9 outs is 19.6% on the river, not 19.1%.
The rule of 2 and 4
You will not do the full calculation at the table. The shortcut is:
- On the flop with two cards to come, multiply outs by 4.
- On the turn with one card to come, multiply outs by 2.
Check it against the exact numbers: 9 outs gives 36% against a true 35.0%; 8 outs gives 32% against 31.5%; 4 outs gives 16% against 16.5%. For 15 outs the rule gives 60% against a true 54.1%, so for big draws subtract the number of outs above 8 (15 − 8 = 7, so 60 − 7 = 53%).
Two warnings. The rule assumes you see both remaining cards, which is not true if you face a bet on the turn and have to pay again, or if an opponent can put you all-in. And outs are only valid when they make the best hand. A card that completes your flush but also completes your opponent’s higher flush is not a clean out.
Worked examples
1. Flush draw, big bet
The flop is Q♠ 7♠ 2♦. You hold A♠ 5♠, so you have a nut flush draw (9 outs). The pot is $60 and your opponent bets $40.
- Pot after the bet: $100. You call $40, giving a final pot of $140.
- Required equity: 40 ÷ 140 = 28.6%.
- Your equity with one card to come is 19.1%. With two cards it is 35.0%.
Which number to use depends on the action. If you will see both cards for free (for example, your opponent is all-in), you have 35.0% and calling is correct. If the opponent can bet again on the turn, you should compare to 19.1% on the next card, and calling fails on price alone. Implied odds may rescue it, as below.
2. Open-ended straight draw, half-pot bet
You hold 8♥ 9♥ on a board of 7♣ 6♦ K♠. Any 5 or 10 completes your straight, giving you 8 outs. The pot is $100 and your opponent bets $50.
- Required equity: 50 ÷ 200 = 25%.
- Your equity to the river is 31.5%; to the next card it is 17.0%.
If this is the only bet you will face, you are comfortably ahead. If you expect another bet on the turn if you miss, you are paying for the draw one street at a time, and the honest comparison is closer to 17% than 31.5%.
3. Gutshot, small bet
You hold 7♣ 9♣ on a board of J♦ 10♥ 2♠ 3♣ (the turn). Only an 8 completes your straight, and there are four of them. Pot $200, your opponent bets $20.
- Required equity: 20 ÷ 240 = 8.3%.
- Your equity on the river: 4 ÷ 46 = 8.7%.
This is a razor-thin call. Anything in the game that nudges it either way, such as an opponent who pays off a made straight, decides it.
Implied odds
Pot odds look at the money in the pot now. Implied odds add the money you expect to win after hitting. The flush draw in example 1 needs 28.6% but has 19.1% to the next card. That gap is 9.5 points, which is large. To justify the call, you would need to win enough extra on later streets when the flush arrives.
A rough check: if you call $40 and hit 19.1% of the time, you need the pot plus later winnings to come to about $40 ÷ 0.191 = $209 on average when you win. The pot would be $140, so you need about $69 more from your opponent on the later streets. That is plausible against a player who pays off a bet, and unlikely against one who folds to your raise or whose hand is weak enough to fold when a third spade arrives.
Implied odds are strongest when:
- Your draw is hidden (a gutshot is harder to see than a flush).
- Your opponent has a big hand he cannot fold.
- Stacks are deep relative to the pot.
They are weakest when the board is scary, your opponent is cautious, or you have little left to bet.
Reverse implied odds are the flip side: you complete your hand and still lose to a better one, as when you hit the low end of a straight and your opponent has the high end.
Common mistakes
- Using the wrong denominator. The call is divided by the pot after you call, not the pot before the bet.
- Using two-card equity when you face a bet on each street. If you must pay again on the turn, compare to the one-card number.
- Counting dirty outs. Outs that complete the board for your opponent too, or that pair the board, are not clean.
- Forgetting the cards you can see. Cards in your opponent’s likely range or already in your hand are not available.
- Over-relying on implied odds. They are a guess about the other player’s behaviour.
- Ignoring that bluffing and folding equity exist. Pot odds assume you only win by hitting. If you can also win by raising and making your opponent fold, your real equity is higher.
- Treating the percentage as a promise. A 35% draw misses almost two times in three.
Try it yourself
Try the outs picker on this site: enter the pot, the bet and your outs, and compare the required equity with the one-card and two-card chances. Try the examples above, then change the bet size to see where a fold becomes a call.
Poker is a game of decisions with money on them, so play at stakes you can afford to lose.
Related guides
- Casino games ranked from best to worst odds: about 30 bets in order, with cost per hour.